The acl_check() function checks the ACL referred to by the argument
acl for validity.
The three required entries ACL_USER_OBJ, ACL_GROUP_OBJ, and
ACL_OTHER must exist exactly once in the ACL. If the ACL contains
any ACL_USER or ACL_GROUP entries, then an ACL_MASK entry is also
required. The ACL may contain at most one ACL_MASK entry.
The user identifiers must be unique among all entries of type
ACL_USER. The group identifiers must be unique among all entries
of type ACL_GROUP.
If the ACL referred to by acl is invalid, acl_check() returns a
positive error code that indicates which type of error was
detected. The following symbolic error codes are defined:
ACL_MULTI_ERROR The ACL contains multiple entries that have a
tag type that may occur at most once.
ACL_DUPLICATE_ERROR The ACL contains multiple ACL_USER entries
with the same user ID, or multiple ACL_GROUP
entries with the same group ID.
ACL_MISS_ERROR A required entry is missing.
ACL_ENTRY_ERROR The ACL contains an invalid entry tag type.
The acl_error() function can be used to translate error codes to
In addition, if the pointer last is not NULL, acl_check() assigns
the number of the ACL entry at which the error was detected to the
value pointed to by last. Entries are numbered starting with zero,
in the order in which they would be returned by the acl_get_entry()
If successful, the acl_check() function returns 0 if the ACL
referred to by acl is valid, and a positive error code if the ACL
is invalid. Otherwise, a value of -1 is returned and the global
variable errno is set to indicate the error.
This page is part of the acl (manipulating access control lists)
project. Information about the project can be found at
http://savannah.nongnu.org/projects/acl. If you have a bug report
for this manual page, see
⟨http://savannah.nongnu.org/bugs/?group=acl⟩. This page was
obtained from the project's upstream Git repository
⟨git://git.savannah.nongnu.org/acl.git⟩ on 2021-04-01. (At that
time, the date of the most recent commit that was found in the
repository was 2021-03-16.) If you discover any rendering problems
in this HTML version of the page, or you believe there is a better
or more up-to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not part
of the original manual page), send a mail to email@example.com
Linux ACL March 23, 2002 Linux ACL